G&F proposes cutthroat trout reintroduction for Porcupine Creek

A proposal to reintroduce the Yellowstone Cutthroat Trout to the Porcupine Creek drainage in the Big Horn National Forest above Porcupine Falls was the topic of a presentation to the Lovell Area Chamber of Commerce Monday.

Fisheries biologist Mark Smith (back of room) talks to the Lovell Area Chamber of Commerce about re-establishing the Yellowstone Cutthroat Trout during the chamber’s general membership meeting Monday. Patti Carpenter photo

Wyoming Game and Fish fisheries biologist Mark Smith explained that he is taking what he emphasized is only a proposal at this time to various groups in order to let the public know what the idea is and to receive input.

“This kind of change may cause anxiety among people close to the resource,” Smith said. “But it’s simply an idea we’re presenting to people to get feedback.”

The reintroduction will only affect the Porcupine drainage about the falls, which Smith said act as a perfect isolating mechanism for the project.

Smith said the Game and Fish proposal is what he called a “flavor change” to change the fishery from the non-native brook trout to the native Yellowstone Cutthroat.

The brook trout is not native to the Western United States and rather is native to the Appalachian Mountains and the Great Lakes region. It was introduced in the West from around 1900 to 1930 and reached the Porcupine drainage around 1932, he said.

“The brook trout does really well in cold water mountain streams like those in the Big Horns,” Smith said, “sometimes too well. They are really good at reproducing.”

Brookies multiply so rapidly that they overpopulate small streams and “eat all the food,” Smith said, stunting the fishery. In Porcupine Creek, the brook trout average only 5½ to 6½ inches in length, and a really big one is 12 inches, Smith said.

Yellowstone Cutthroats also do well in high mountain streams, but they don’t compete well with other trout, Smith said, adding, “You can’t let any other fish be with them or they will disappear.” Alone, he said, they reproduce well, but they don’t overpopulate the stream.

Whereas brook trout will fill a stream with 2,500 fish per mile, cutthroats top out at 800 to 900 fish per mile, Smith said, so they are able to grow larger, averaging seven to eight inches with individuals up to 14 or 15 inches in length.

“You have fewer fish but bigger fish,” Smith said.

Smith told of a raft trip down the Big Horn River in 1893 during which an avid fisherman on the expedition fished Porcupine Creek at its confluence with the Big Horn and caught 25 cutthroat trout ranging from 18 to 25 inches in length. He said the fisherman may have exaggerated the size of the fish, but the story shows the kind of fishery that once existed. He said in the 1890s cutthroats also thrived in drainages like the No Wood, Shell Creek, Crooked Creek and others.

Smith said after the turn of the century people got very good at propagating fish, learning that fish eggs could be easily transported in milk cans loaded with ice. He said people took a “Johnny Appleseed” approach, spreading various species of fish wherever they felt like it. Into the West came brook trout native to West Virginia and New York, Brown trout native to Scotland and Germany and rainbow trout native to California and Oregon.

There are now only 12 populations of cutthroats on the west side of the Big Horns, Smith said, in 76 stream miles, and many are in the midst of a brook trout onslaught. The two streams where cutthroats are doing fairly well are Cedar Creek in the Shell drainage and Trout Creek in Cookstove Basin, but those streams are difficult to access for anglers.

Smith said he would like to take his daughter fishing to a place where anglers can enjoy fishing for native fish in their native environment.

The project

Smith said the idea is to totally remove brook trout from the fishery above Porcupine Falls, and it is impossible to “hook and line” the fish from the stream due to their prolific reproduction.

“It you leave two, it’s a complete failure,” he said.

Thus, the only tool the Game and Fish has is to chemically remove the brook trout using Rotenone, a naturally-occurring organic compound that is highly toxic to organisms with gills. He said it has been used for thousands of years and has many applications.

To kill fish, the Rotenone would be applied to the stream via a drip system and will kill 99.9 percent of the fish over a period of eight hours. But 99.9 percent isn’t enough with brook trout, so the Game and Fish would re-apply the chemical for two more years, as well, to make sure.

Rotenone breaks down rapidly, Smith said, in 1½ to 2 hours, and it binds to soil so completely that it won’t seep into groundwater. The drip system would be placed every quarter of a mile or so to maintain toxicity in the stream. Below the target area, another chemical – potassium permangenate, would be used to break down the Rotenone.

After the application, the stream would be stocked with “catchable size” Yellowstone Cutthroats so there is no down time for the fishery. The Game and Fish would concentrate on areas near popular fishing holes and campgrounds. Cutthroats would be “aggressively stocked” after each stream treatment, he said.

Smith emphasized that the project is currently a proposal, not a done deal, and the Game and Fish wants to hear from people who use the resource. He said it would probably be 2013 before the agency performs the operation, if it is approved. He said re- establishing cutthroat trout would likely double, if not triple, interest in Porcupine Creek as a fishery.

He said the water would be probably treated in early August and re-stocked each year with cutthroat trout a couple of weeks later.

“There would be a short time period when there would be no fish to catch,” Smith said.

Those who would like to provide input on the project may contact Smith at 2820 State Highway 120, Cody, WY 82414 or e-mail comments to Mark.Smith@wgf.state.wy.us. Or call 307-527-7125.